Many anaerobic curing adhesives which are in liquid states when they are in contact with air but are cured when they are isolated from air in the case of existing in, for example, the gap between metals, etc., are known and utilizing the feature of these adhesives, they are widely used for fixing screws, sealing piping portions or flanged portions, fixing fitted portions, etc. Recently, there is a strong tendency of automating the assembling work of electric machinary parts, machine parts, etc., for the speed up of and labor-saving for the work and with such a tendency, a greatly quick curing property has been required for adhesives used in the work. Also, many plated materials are used as the parts in the foregoing assembling work for preventing the occurrence of corrosion and hence the development of one-part anaerobic curing adhesives showing quick curing property for plated materials has been desired.
However, conventional anaerobic curing adhesives are insufficient in adhesive speed for being used in automation line and this tendency is particularly remarkable for plated materials. Thus, in the case of using conventional anaerobic curing adhesives, complicated operations such as the use of a primer and the employment of heat curing are required.
As the result of various investigations for obtaining anaerobic curing adhesives showing a quick curing property for not only active metals such as iron series metals and copper series metals, etc., which are no subjected to surface treatment (hereinafter, are referred to as active metals) but also plated metals (hereinafter, is referred to as inactive metals), the inventors have discovered that a composition prepared by adding o-benzoic sulfimide, a heterocyclic tertiary amine and/or an aromatic tertiary amine, a radical polymerization initiator, and water to a hydrophilic anaerobic polymerizable monomer which can contain a small amount of water shows a very quick curing property for various metals including inactive metals.
Examples of using o-benzoic sulfimide and amines as a curing accelerator for anaerobic curing adhesives are disclosed in U.S. Pat. Nos. 3,043,820 and 3,218,305. In the latter patent it is described that a good adhesive speed for active metals is obtained in the case of using an amine selected from the group consisting of aromatic tertiary amines and heterocyclic secondary amines where in the heterocyclic ring is hydrogenated.
The inventors have discovered that when a definite amount of water is added to the foregoing composition containing the aromatic tertiary amine, the composition shows very fast curing property for not only active metals but also inactive metals. Furthermore, it has been discovered that a heterocyclic tertiary amine which does not provide so much quick curing effect for the conventional anaerobic composition provides remarkable quick curing property for the composition for not only active metals but also inactive metals if a definite amount of water exists in the system. It has further been discovered that among heterocyclic tertiary amines, quinolines and quinoxalines show more remarkable effects in the foregoing composition.
The present invention has been attained based on the foregoing discoveries.